As for your specific request, go to T1 enter"=" and click "A1".
This way upon entering a data into A1, it will be automatically entered to
T1 as well. If you want to repeat it for other rows in column T, drag the T1
up to desired row.
Is this you question?

"RW" wrote:

Is there a way to automatically populate a cell with the same data that is
entered into a different cell?

Say for example I have a 20 column wide spreadsheet. When I enter data into
the cell at row 1, column 'A', I want that data to automatically be entered
into the cell at row 1, column 'T'.

Can this be done? Can I link entire columns?